Measurement & Experimentation Laboratory

This course will serve as your introduction to working in an engineering laboratory. You will learn to gather, analyze, interpret, and explain physical measurements for simple engineering systems in which only a few factors need be considered. This experience will be crucial to your success in analyzing more complicated systems in subsequent coursework and in the practice of mechanical engineering.

We frequently encounter measurement systems in our everyday lives. Consider the following examples:

1. The many gauges found on the control panel of a motor vehicle indicate vehicle speed, engine coolant temperature, transmission setting, cabin temperature, engine speed, and oil pressure—amongst many other measurements.

3. The experienced cook may use several measurements to successfully “cook until done”—for example, he or she might measure internal temperature, external coloration, external temperature and exposure time, internal coloration, aroma, and texture.

Any one of these measurement systems may require substantial attention to detail. Consider the elaborate ritual of procedure that occurs next time you have your blood pressure measured in a routine physical examination. Or perhaps observe the careful baker measuring the temperature in the final stages of baking. You might ask: “What type of thermometer is used? How large is the probe? What is the response time of the probe (how long do we have to let it equilibrate for each measurement)? What is the accuracy of the measurement? What is the precision of the measurement? Where in the product are the measurements taken? How many measurements are taken? How are the measurements recorded? And finally, what possible actions might be taken as a result of those measurements?”

The primary purpose of this course is not to make you an expert at all types of measurements important to mechanical engineering, but rather to expose you to the use and analysis of a few such techniques so that you may readily adapt new techniques as appropriate in subsequent coursework and in your engineering career. Each section of this course is accompanied by hands-on or virtual exercises. The units of this course are intended to stand alone, but you may find it worthwhile to revisit previous sections and exercises after completing later sections of the course.

Primary Resources: This course comprises a range of different free, online materials. However, the course makes primary use of the following:

All About Circuits

Requirements for Completion: In order to complete this course, you will need to work through each unit and all of its assigned material. All units build on previous units, so it will be important to progress through the course in the order presented.
Note that you will only receive an official grade on your Final Exam. However, in order to adequately prepare for this exam, you will need to work through the assessments at the end of each unit in this course.

In order to pass this course, you will need to earn a 70% or higher on the Final Exam. Your score on the exam will be tabulated as soon as you complete it. If you do not pass the exam, you may take it again.

Time Commitment: This course should take you a total of approximately 111 hours to complete. Each unit includes a time advisory that lists the amount of time you are expected to spend on each subunit and assignment. These time advisories should help you plan your time accordingly. It may be useful to take a look at the time advisories before beginning this course in order to determine how much time you have over the next few weeks to complete each unit. Then, you can set goals for yourself. For example, Unit 1 should take you approximately 19 hours to complete. Perhaps you can sit down with your calendar and decide to complete Subunit 1.1 (a total of 4 hours) on Monday night, Subunit 1.2 (a total of 6 hours) on Tuesday and Subunit 1.3 and 1.4 (3 hours) on Wednesday night, etc.

Tips/Suggestions: It is extremely important that you give each assignment the amount of reading and review necessary to grasp the main points and lines of enquiry. Also, on completing the assessments, take a moment to consider how the materials you have just studied relate to the topics covered in previous sections of the course.

This course features a number of Khan Academy™ videos. Khan Academy™ has a library of over 3,000 videos covering a range of topics (math, physics, chemistry, finance, history and more), plus over 300 practice exercises. All Khan Academy™ materials are available for free at www.khanacademy.org.

Instructions: Please skim the preliminary chapter of this text in order to familiarize yourself with the common measurements and systems of units used. Pay particular attention to Sections 3: “Energy, Heat, and Temperature: An Introduction,” 4: “Units and Dimensions,” and 5: “The Meaning of Measure.” You will learn more about the details of the use of such units in later sections of the course.

Instructions: Click the link for the PDF Experimentation and Measurement under the heading “Calibration Related Publications.” Read the Forward, the Preface, and the first three Chapters. This is friendly, relaxing reading. You may be concerned that the material appears out-of-date, but part of the purpose of the reading is to acquaint you with some recent historical context for experiment and measurement techniques.

Unit 1: Scientific Notation, Data Analysis, and Experimental Error

This unit consists of a review of some basic concepts you may remember from courses in mathematics and experimental science. You may skim through the material, but you will need to be precise in later work about the nomenclature used for reporting errors and statistics. The reference immediately below is a handbook for engineering statistics; it is not meant to be read from start to finish but rather to be used as a reference for specific problems at hand. You may wish to familiarize yourself with the nomenclature and organization of the handbook.

1.1.2 Significant Figures

Also available in:PDFEPub Format
Instructions: Read these notes and pay particular attention to the effect of mathematical operations upon significant figures. For example, consider how many significant figures might be in the result of the operation 1.23(4.4/6,873 +2.0).

Instructions: Read the linked section above on descriptors of averages. Note that there are other descriptors (besides the mean and median) that may be useful. As you read, you may wish to consider hypothetical cases in which the median might be more useful than the mean.

Instructions: Read the linked section on the properties of the Normal or Gaussian distribution. Pay attention to the significance of the mean and standard deviation to the position and width of the distribution.

Instructions: Review this section, ensuring that you are able to distinguish between random error, systematic error, accuracy, and precision. This reading addresses sections 1.4.1 and 1.4.2. To view as a PDF, click the “download” link in the bottom right corner.

Instructions: Read this section and the links titled “Least Squares” and “Weighted Least Squares.” This information may seem rather technical at the moment, but as you gain experience with using the methods, it will make more sense to you.

Terms of Use: This material is in the public domain.

1.7 Exercises

1.7.1 Calculation of Mean, Standard Deviation, and Variance

Instructions: Read the linked section above. Perform the calculations of statistics as prompted. You may wish to experiment with peculiar distributions exhibiting distinctive shapes (such as bimodal, triangular, or square distributions) and compare them with other distributions.

Terms of Use: The material above has been reposted with permission for educational use by Thomas W Kirkman. It can be viewed in its original form here.

1.7.2 Linear Least-Squares Estimates of Slope and Intercept

Instructions: This section caters to those with an abstract, mathematical bent. You can develop some appreciation for the concepts involved by skimming the text and studying the graphs as examples rather than by trying to understand the details of the mathematical analysis. Note that this material may be more appealing after you have some experience using the methods.

Terms of Use: Please respect any copyright and terms of use displayed on the webpage above.

1.7.3 Nonlinear Regression

Instructions: Drag data points from the data-point-bin onto the graph. Adjust the error bars. Examine the best-fit curves for different situations. You should play with this exercise to get an intuitive feel for how data and error bars affect the best fit curves. Please also try to fit data with different types of curves (for example, lines and higher order polynomials). By playing around with this online demo, you can quickly obtain experience that can be easily applied to concrete situations.

Unit 1 Assessment

Instructions: Please complete the linked assessment.

You must be logged into your Saylor Foundation School account in order to access this exam. If you do not yet have an account, you will be able to create one, free of charge, after clicking the link. This quiz should require less than one hour to complete.

Unit 2: Graphical and Tabular Data Presentation

Standard styles for presenting data in graphical and tabular form have evolved over time for efficiency of data communication. Contemporary computer tools for data presentation allow us to use such styles in order to generate graphics. Even with these tools, the user must still determine the most appropriate format for conveying the desired information and appropriately labeling the graphic. This unit will introduce several formats for concise data presentation that will be useful in subsequent work.

You probably have access to several utilities for creating graphical presentations of data. The list below contains topics that you should explore in your own graphical data analysis utility. As a start, you may wish to read or refer to one or more of the following. After you have skimmed these resources, you should review them to make sure that you have a grasp of the following concepts. You should practice using each of the ideas below in a computer environment of your choice.

Instructions: If in need of inspiration for graphical analysis and presentation of data, it may be helpful to refer to the linked material above. Many of the plotting techniques are useful for very specific experimental situations. You may wish to skim through a few of the descriptions to get a feel for the types of plots that other people have used.

Instructions: Read this (tongue-in-cheek) document. Although many of the tips may seem obvious, it is important to have such a list of common errors in mind when creating a graph for a document in the late stages of preparation, when all participants are tired and the thinking may not be clear.

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

Instructions: Scroll down to about halfway down the page and download the “Excel(2003)” file under “Data Handling and Analysis….” Read this pamphlet and learn to manipulate data in a spreadsheet in order to create a graph.

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

2.1.3 Scatterplots

2.2 Labels

2.3 Error Bars

Unit 2 Assessment

Instructions: Please complete the linked assessment.

You must be logged into your Saylor Foundation School account in order to access this exam. If you do not yet have an account, you will be able to create one, free of charge, after clicking the link.

Unit 3: Electrical Circuits and Measurements

A review of basic circuit principles and measurements is included here for completeness, but you should refer to PHYS102: Introduction to Electromagnetism for a discussion of the fundamental physics. In this unit, you will review elementary concepts of circuit analysis for utility in signal transduction, conditioning, and measurement.

Note: Much of the material in Units 3 and 4 are interdependent and refer you to discussion available in the resource “All About Circuits”; you are encouraged to peruse that resource in full at your own pace if you do are not familiar enough with concepts in electrical engineering to understand the material as it is presented here. In addition, many of the sections in “All About Circuits” contain example problems that you should follow and review for particular emphasis.

Note: There is a review quiz for both Units 3 and 4 at the end of Unit 4.

3.1 Standards and Units

Instructions: Read Chapter 1. You may skim this material if you are already familiar with it, but it is light, non-mathematical reading. You may benefit from the analogy of fluid flow and electrical flow. To view as a PDF, click the PDF link in the top right corner.

3.2 Elementary Circuit Elements

3.2.1 Resistors

Instructions: Read Chapter 2. Again, you may skim the chapter if you are already familiar with the concepts. You may wish to practice with calculations of power, current, voltage, and resistance. To view as a PDF, click the PDF link in the top right corner.

3.2.2 Inductors

Instructions: Read Chapter 3. You have already read Chapter 1 on Basic AC Theory, but you may wish to reread it and then refresh your memory by reading Chapter 2 on complex numbers. To view as a PDF, click the PDF link in the top right corner.

3.2.3 Capacitors

Instructions: Read Chapter 4. You may find the section on “Capacitor Quirks” mildly amusing. The text does not emphasize the units, but you may wish to look at the size of typical capacitors you might find in electrical appliances. To view as a PDF, click the PDF link in the top right corner.

Instructions: A firm grasp of the concept behind and applications of Kirchoff’s laws is a must. You may wish to practice by following along with the calculations in this section. To view as a PDF, click the PDF link in the top right corner.

3.4 Elementary Measurements

Instructions: Read the linked section above. At this stage, you should skim through the material and gather materials together for exercises that will be performed later. To view as a PDF, click the PDF link in the top right corner.

3.5.2 Signal Amplifiers

Instructions: Read the linked section above. You may wish to pay particular attention to the definition and use of the unit decibel or dB and work along with the examples. To view as a PDF, click the PDF link in the top right corner.

Instructions: Read the linked section above and perform measurements as possible. To view as a PDF, click the PDF link in the top right corner.

Unit 4: Computer Assisted Data Acquisition

Current data acquisition methods often employ electronic signal transduction and digital recording for subsequent analysis. Since these methods are so widespread and since errors in inappropriate implementation may manifest differently than they would if you were to make the same mistake reading a meter, you should understand some of the details of the process and some of the common artifacts of inappropriate implementation. Consider, for example, the differences between an artifact observed in imperfect digital versus imperfect analog imagery or audio reproduction.

Note: Much of the material in Units 3 and 4 are interdependent and refer you to material in “All About Circuits”; you are encouraged to peruse that resource in full at your own pace if you are not familiar enough with concepts in electrical engineering to understand the material as it is presented here.

4.1 Analog Signal Processing

Instructions: This section should provide you with enough background information to understand analog signals in general and pneumatic and electrical signals in particular. The analogy between fluid and electrical systems may appeal to those with practical fluid mechanics experience. To view as a PDF, click the PDF link in the top right corner.

Instructions: These sections introduce alternating current (AC) signals. The material is rich; you may wish to revisit the sections after the initial study. The main idea is that steady signals permit the communication of only one piece of information: the amplitude of that signal. By combining that amplitude with measurements of time, we can communicate a new piece of information at each new time. Schemes for encoding information into signal amplitude and time variation can be quite complex; take, for example, the different communication protocols for radio, television, cellular telephone, etc. In order to understand these technologies, you must have a firm grasp of the underlying physics and mathematics of time-varying signals.

You should first skim the above sections and flag any topics or symbols that you do not understand. You may then revisit these sections after you have completed both Units 3 and 4 in their entirety. To view as a PDF, click the PDF link in the top right corner.

Instructions: Read these sections; they introduce the ideas and circuit symbols for ideal current and voltage sources and present background material on their utility and non-idealities. At a minimum, upon completing this reading, you should be familiar with the symbols involved for future study. To view as a PDF, click the PDF link in the top right corner.

4.1.3 Filtering

Instructions: Read the linked chapter on filters. The text is sufficiently self-explanatory and contains an introductory discussion. You might wish to keep in mind the following questions: How can digital signal processors be used to build filters? Is it necessary to use analog filtering devices? To view as a PDF, click the PDF link in the top right corner.

Instructions: Read the linked sections above and perform measurements as possible. You needn’t become an expert at bridge design, but rather your aim should be to become familiar with the terminology and use of bridge circuits. To view as a PDF, click the PDF link in the top right corner.

4.2 Digitization

Instructions: Read the linked section above for an introduction to relevant terminology. You should understand the relationship between analog signals, digital signals, and binary numbers. To view as a PDF, click the PDF link in the top right corner.

Instructions: Read the linked section. Focus on the two topics (i.e. the headings for subunits 4.2.1 and 4.2.2) listed below. For example, you might keep the following questions in mind: What is the percent linear resolution in a 24-bit binary encoding? How often must sound be sampled in order to accurately represent 20 kHz signals to the ear? To view as a PDF, click the PDF link in the top right corner.

4.2.1 Number of Bits or Resolution

4.2.2 Sampling Rate

4.3 Common Artifacts from Improper Digitization

Note: The most common artifacts from digitization occur as a result of inappropriate sampling rate and/or signal amplitude. In principle, these problems are similar to, for example, seeing only every hundredth frame in a video presentation or having the volume knob up way too high on an audio presentation. There are, however, many other subtle artifacts which may emerge upon close scrutiny. You may be familiar with the vast difference in the sorts of problems that occur with digital television or cell phone transmission versus analog transmission. Likewise, problems may manifest differently depending upon the processing that is used to get from the original digital signal to the result.

4.4 Tutorial for a Commercial Data Acquisition System

Instructions: Familiarize yourself with the capabilities of this virtual instrumentation environment. This is an example of common functionality for such a system in a laboratory. If you have access to a similar system, take the time to acquaint yourself with it.

Units 3 and 4 Assessment

Instructions: Please complete the linked assessment.

You must be logged into your Saylor Foundation School account in order to access this exam. If you do not yet have an account, you will be able to create one, free of charge, after clicking the link.

Unit 5: Measurements of Linear Dimension

The measurement of length is as fundamental to mechanical engineering as it is to everyday life (consider the variety of length scales we use on a day-to-day basis: the hand, finger, foot, rod, nose, and hair!) Coupled with other information, length measurements can yield complex geometric information. In this unit, you will learn about a few tools that enable us to precisely measure lengths and related quantities over vastly different length scales. Many more tools are available than can be described here.

Instructions: Review this chapter, focusing on the short section on length. Note that there may be an error in the figure on length scales regarding the size of a hydrogen atom. Look up the size elsewhere and compare. To view in a PDF file, scroll to the bottom and click on the “download” link.

5.2 Calipers

Note: Calipers are claw-like devices used for measuring linear dimension. They are particularly useful for measuring the outer diameters of cylindrical or round objects or the internal diameters of pipes and the like. They are one of the few instruments that still makes use of Vernier scales.

Instructions: Read this discussion of the Vernier scale and test your knowledge with the Java applet. If you have access to a set of calipers, you may wish to practice with measuring the thickness of a series of nominally identical coins.

5.3 The Sine Bar

Instructions: View this slide show, which demonstrates the use of a sine bar for measuring angles. The sine bar is often used in conjunction with gauge blocks in machine shops for precise manufacturing of equipment. You may wish to review the trigonometry involved in the use of sine bars.

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

5.4 Instrumentation

Instructions: Modern instrumentation is capable of precise and accurate measurements of lengths over many length scales. The most current information about commercially available instrumentation is readily accessible via informational advertisements on YouTube. For each of the following items (5.4.1-5.4.5 listed below), review at least one such advertisement and answer the following questions:

1. What are the technical capabilities of the instrument?
2. What is the cost of the instrument?
3. What is the level of training required to operate and obtain meaningful data from the instrument?
4. What types of systems are amenable to study by the instrument?

In your search, you may find many other types of instrumentation for similar purposes with slightly different names. The list bellow will help you get you started.

5.4.5 Global Positioning System Measurements

Unit 5 Assessment

Instructions: Please complete the linked assessment.

You must be logged into your Saylor Foundation School account in order to access this exam. If you do not yet have an account, you will be able to create one, free of charge, after clicking the link.

Unit 6: Time Measurements

Throughout history, we have marked time by the motion of objects in the sky that indicate the passage of hours, days, months, and years. More accurate measures of time gradually emerged in response to the demands of navigation, commerce, communications, and curiosity. Today, atomic clocks operate with a time resolution of one part in 1015.

In this unit, you will learn about standards of time measurement, the limits of human reaction times, and the practical limits of precise time measurement via readily available, computer-based sensors.

6.1 Human Reaction Times

Note: When performing any physical measurement, you must know the limits of the measurement system you are using. Here, we will briefly explore the limits of human reaction times.

6.1.1 Dropping Meter Stick Exercise

Instructions: Estimate the time required for a person to let go of a meter stick and grasp it again by measuring the distance that the meter stick falls under the acceleration of gravity. You will need to use Newton’s laws and some simple calculations to determine that d= at2/2 where d = the distance dropped, t= the reaction time, and a= the acceleration of gravity. Repeat the measurement several times for several different individuals. Calculate statistics (e.g. means, standard deviations).

6.1.2 Flashing Light Exercise

Instructions: Estimate human reaction time by performing a computer- based reaction time test (i.e. press a mouse button when the light flashes). Compute the mean reaction time for an individual and the standard deviation of reaction times for that individual. Compare that reaction time with the one determined from the meter-stick experiment.

Terms of Use: This material is in the public domain.

Unit 6 Assessment

Instructions: Please complete the linked assessment.

You must be logged into your Saylor Foundation School account in order to access this exam. If you do not yet have an account, you will be able to create one, free of charge, after clicking the link.

Unit 7: Force, Torque, and Pressure Measurements

Force, torque, and pressure measurements can be related by temporal and geometric coupling. Consider the schematic of a see-saw balance.The relative masses of objects M1 and M2 can be determined by the torques they exert about point P at different distances (L1 and L2) from that point under the acceleration of gravity g. Many more sophisticated geometries and sensing arrangements can be coupled to allow measurements of related quantities. In this unit, you will review some of the common configurations for such measurements.

7.1.3 Strain or Deflection Measurements

Instructions: Read this section and consider the following issues: Why does the resistance of the strain gauge depicted in the resource cartoon increase under tension? How might strain measurements be confounded by changes in temperature? Might you design a strain gauge to work by measuring changes in capacitance? To view as a PDF, click the PDF link in the top right corner.

Note: These concepts arise from Bernoulli’s equation. They are not to be confused with Gauge and Absolute pressures. Gauge pressure is the system pressure minus some reference (atmospheric pressure).

Instructions: Read the two web pages linked above and consider the following issues: Do static and dynamic pressures have the same units? What is the origin of the terminology? How would you use measurements of both to determine the speed of an airplane?

Terms of Use: This material is in the public domain.

7.2.3 Barometers and Manometers

Instructions: Read the linked page above and those following as interested. Consider the following questions during your reading: What is the difference between a barometer and a manometer? Why is mercury often used as the fluid in a manometer? Why might one use another fluid? You may wish to play with the applet to consider the effects of fluid properties on the observed measurements.

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

Instructions: Read the first three sections in the linked material above, entitled “What is Pressure?”, “The Pressure Sensor,” and “Pressure Measurement.” What factors influence the time-response of a pressure transducer?

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

7.3 Torque Measurements

Instructions: This video should be a review of concepts you learned in physics coursework. You may refer to previous or subsequent videos in the series if you need additional exposure. Make sure you understand appropriate units for torque.

Instructions: Perform the same exercise on YouTube for dynamometers as you did for length measurement devices in Section 5.4 of this course.

Unit 7 Assessment

Instructions: Please complete the linked assessment.

You must be logged into your Saylor Foundation School account in order to access this exam. If you do not yet have an account, you will be able to create one, free of charge, after clicking the link.

Unit 8: Temperature Measurements

Temperature control is fundamental to most chemical, biological, and mechanical processes. In order to determine which temperature sensor or transducer is appropriate for a given situation, you must consider a number of factors, including operating environment and desired temporal and measurement sensitivity. In this unit, you will review common temperature scales and the characteristics of commonly-used temperature measuring devices.

Instructions: Read the text and then calculate the following: room and body temperature in degrees Fahrenheit, Centigrade, Kelvin, and Rankine. What is the meaning of negative absolute temperature?

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

8.2 Expansion Thermometers

Note: You are probably familiar with the liquid-in-glass expansion thermometer, although its use is declining with time. You may have encountered one in a chemistry laboratory, in cooking candy, or for a body temperature measurement. Another type of expansion thermometer makes use of the differential expansion of two metals and is hence called a bimetallic expansion thermometer. These have been used in devices like thermostats, in which some mechanical action is required as a function of temperature.

Instructions: You may use this resource as a quick reference for terms that you do not understand and as a survey for many other temperature measurement methods. There is an accompanying video link embedded in the wiki pages (HTML).

8.4 Thermocouples

Instructions: Read the text linked above and consider the following questions: How is temperature related to thermocouple voltage? What types of metals are used for thermocouples? Over what temperature ranges are thermocouples appropriate?

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

Instructions: Read the linked section above, which is particularly useful for understanding the importance of the reference junction to thermocouple operation. To view as a PDF, click the PDF link in the top right corner.

8.5 Dynamics of Sensors

Instructions: Read the linked section above. How do you expect the response time of the sensor to scale with the size of the sensor? You will make use of this knowledge in Exercise 8.6.

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

8.6 Exercise: Dynamics of a Temperature Measurement

Instructions: Select a thermometer and record information concerning the origins and type of the device. Some common types of kitchen thermometers would be suitable. Tabulate and plot the temperature reading versus time after removing the device from ice water and placing it in boiling water or room temperature water. Make sure that the thermometer has equilibrated with the ice water before removing it and that the volumes of the water baths are much larger than that of the sensor. How long does it take the thermometer to reach 95% of its change in reading? Repeat the measurements. For each trial:

1. Plot temperature as a function of time.2. Plot (T(t)-Tfinal)/(Tinitial-Tfinal) versus time, where Tfinal is the temperature of the hot water, Tinitial is the temperature of the cold water, and T(t) are the temperature readings.3. Plot the logarithm of (T(t)-Tfinal)/(Tinitial-Tfinal) versus time.4. What is the slope of the curve in 3?5. What is the response time of your thermometer?

Unit 8 Assessment

Instructions: Please complete the linked assessment.

You must be logged into your Saylor Foundation School account in order to access this exam. If you do not yet have an account, you will be able to create one, free of charge, after clicking the link.

Unit 9: Dynamic Measurements and Control

In this unit, you will implement what you learned in previous units to make dynamic measurements and use these measurements in order to control a piece of equipment. In lieu of performing the actual exercise, you will write a detailed procedure and submit hypothetical data for two of the following topics. The topics are intentionally open-ended so that you have the freedom to define the problem as your resources permit. Each report should consist of the following elements.

9a. Introduction: Explain the exercise in the broader context of mechanical engineering.9b. Purpose: Briefly explain the specific, limited objectives of the exercise.9c. Equipment: Where possible, list commercially-available equipment, complete with all available specifications.9d. Procedure9e. Theory: Outline the physical basis for the measurements and the details of data analysis.9f. Hypothetical Data: Generate hypothetical data, complete with estimated errors.9g. Analysis of Data and Presentation of Results9h. Recommendations for Future Experimenters

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

Instructions: Read both sections and model your reports after them. To view as a PDF, click on the PDF link in the top right corner.

Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.

9.1 Dynamic Strain Measurements

Instructions: Design an apparatus that can observe the oscillations that occur when a cantilevered beam is suddenly loaded with a weight. You may use commercially available strain gauges.

9.2 Accelerometry

Instructions: Design an apparatus to measure the acceleration that occurs when a stationary object is suddenly hit by a moving object (e.g. a mass swinging from a pendulum).

9.3 Temperature Control of a Light Bulb

Instructions:An incandescent light bulb dissipates most of its energy as heat. By adjusting the duty cycle of the bulb (i.e. by turning it on and off to control the amount of heat dissipated), one can control the temperature of the surface of the bulb. It is your task to choose an appropriate temperature sensor and design a feedback control algorithm to keep the surface temperature at a set point by adjusting the amount of time that the bulb is lit versus dark.

Final Exam

Instructions: You must be logged into your Saylor Foundation School account in order to access this exam. If you do not yet have an account, you will be able to create one, free of charge, after clicking the link.